From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 07D806B0011 for ; Mon, 9 May 2011 19:04:49 -0400 (EDT) Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e2.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p49MiwpH011463 for ; Mon, 9 May 2011 18:44:58 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p49N3j3q046864 for ; Mon, 9 May 2011 19:04:06 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p49J3WXu026438 for ; Mon, 9 May 2011 16:03:33 -0300 Subject: [PATCH 3/7] mm: Provide stub page_mkwrite functionality to stabilize pages during writes From: "Darrick J. Wong" Date: Mon, 09 May 2011 16:03:41 -0700 Message-ID: <20110509230341.19566.3876.stgit@elm3c44.beaverton.ibm.com> In-Reply-To: <20110509230318.19566.66202.stgit@elm3c44.beaverton.ibm.com> References: <20110509230318.19566.66202.stgit@elm3c44.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Theodore Tso , Jan Kara , Alexander Viro , OGAWA Hirofumi , "Darrick J. Wong" Cc: Jens Axboe , "Martin K. Petersen" , Jeff Layton , Dave Chinner , linux-kernel , Dave Hansen , Christoph Hellwig , linux-mm@kvack.org, Chris Mason , Joel Becker , linux-scsi , linux-fsdevel , linux-ext4@vger.kernel.org, Mingming Cao For filesystems that do not provide any page_mkwrite handler, provide a stub page_mkwrite function that locks the page and waits for pending writeback to complete. This is needed to stabilize pages during writes for a large variety of filesystem drivers (ext2, ext3, vfat, hfs...). Signed-off-by: Darrick J. Wong --- mm/filemap.c | 19 +++++++++++++++++++ 1 files changed, 19 insertions(+), 0 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index fd0e7f2..1e096a0 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1713,8 +1713,27 @@ page_not_uptodate: } EXPORT_SYMBOL(filemap_fault); +static int empty_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct inode *inode = vma->vm_file->f_path.dentry->d_inode; + loff_t size; + + lock_page(page); + size = i_size_read(inode); + if ((page->mapping != inode->i_mapping) || + (page_offset(page) > size)) { + /* page got truncated out from underneath us */ + unlock_page(page); + return VM_FAULT_NOPAGE; + } + wait_on_page_writeback(page); + return VM_FAULT_LOCKED; +} + const struct vm_operations_struct generic_file_vm_ops = { .fault = filemap_fault, + .page_mkwrite = empty_page_mkwrite, }; /* This is used for a general mmap of a disk file */ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org